Many new and existing golf courses have narrowed their fairways and expanded their rough areas on either side of the fairways. Roughs requires less care than fairways, so narrowing the fairways allows golf course operators to lower their maintenance costs. For example, irrigation requirements may be reduced if only the fairways are watered. If grasses in the roughs are allowed to grow longer, those non-irrigated areas are less brown. Trees and other aesthetic features may be located in the roughs, because roots and shade can inhibit turf growth in the fairways.
However, golf course roughs still must be maintained regularly using grass mowing machines that can mow the vegetation at an acceptable length and appearance. Equipment for mowing golf course roughs typically includes a traction vehicle carrying three or five rotary cutting decks, each rotary cutting deck mounted on the end of a lift arm extending from the traction vehicle. Carrying the rotary cutting decks with lift arms extending from the front or sides of the traction vehicle is necessary and desirable, instead of towing the rotary cutting decks behind the vehicle, because it is necessary for the mower to provide close trims next to trees, bunkers or other hazards. Each lift arm also may be used to move a rotary cutting deck between a mowing position and a transport position. The mounting devices also should allow for pitch (front to back pivoting) and yaw (side-to-side pivoting) of the rotary cutting decks.
Traction vehicles carrying rotary cutting decks may travel at speeds of 6 to 8 miles per hour when mowing golf course roughs. The traction vehicle's weight may be in excess of 2000 pounds. Each rotary cutting deck may be subject to shocks from impacts against the ground surface or objects during mowing. To withstand the rigorous mowing conditions, rotary cutting decks typically are made of thick sheet steel, such as 7 gage or 10 gage sheet steel. Each rotary cutting deck may have a diameter between about 18 inches and 27 inches, and weigh at least 120 pounds.
Golf course operators sometimes need to change the height of cut of rotary cutting decks on a rough mower. For example, the height of cut may need to be changed if the mower goes from an intermediate rough with a 1½ to 2 inch height of cut, to a full length rough with a 3 to 4 inch height of cut. The height of cut also may need to be changed if the machine is used to mow rough for tournaments where rough heights can be as long as 6 inches. Additionally, golf course operators may change the height of cut of a rotary cutting deck due to seasonal variations, shade conditions, or different types of grass or vegetation in different rough areas of a golf course.
For a grass mowing machine with multiple rotary cutting decks mounted on lift arms, a height of cut adjustment mechanism is needed that is rugged, reliable, relatively simple and inexpensive. A height of cut adjustment mechanism for rotary cutting decks on a rough mower is needed that can absorb shocks from impacts and provide good stability of each deck at specified cutting heights.